In designing and building electrical circuits, it is often necessary to include snubber circuits to damp spurious transients or oscillations. Often these employ resistors and capacitors in the familiar R-C snubber circuit, usually with the R-C in series across a switching means or rectifier, but sometimes other arrangements are used.
Snubber circuits assembled of components with leads are less effective at high frequencies because the "lead inductance" becomes a significant impedance at high frequencies. Therefore it has become common to employ lossy inductive components as snubbers. These are often in the form of a bead of magnetic material such as a ferrite bead or powdered iron bead or the like which can be slipped over one of the conductors of the circuit.
For many applications, it is impossible to find a suitable lossy inductive bead which will effectively damp an oscillation without introducing excessive losses or time delays or consuming too much energy.